Need Help And Advice For My Brackish Tank Problems

[ac106]

Hi all,

I have had a brackish tank set up for about 5-6 months.

Specs
29G tank
Crushed coral substrate
SG ~ 1.005,
Temp ~77F (reduced from 80F)
PH is pretty high. It's 8+ out the tap and higher then my kit goes
Filtration: 2 Aquaclear 30s and 1 box filter with floss and biomax.
Fishless cycle, ammonia and nitrite have been consistently at 0
Weekly water changes of about 5g
-Always drip acclimate new fish

Here is the issue (s) When i set this tank up I did a fishless cycle and then added 2 knight gobies, 1 figure 8 puffer, dragon goby and a GSP.

This went well for about a month or so, then the dragon jumped out and died. Found him a couple days later and was distraught. Bought another dragon, and soon after 2 orange chromides and an Archerfish. Everything went well for a while but then the dragon died. I think he starved to death. Without a sand substrate he couldn’t properly filter feed. I did hand feed him with a medicine dropper but I suspect it wasn’t sufficient. I didn't try a third (and won't without sand.)

Ok after a few weeks of no deaths and everything going good. I get 2 kribs. Drip them over several hours. They seem to do fine for maybe a week or two. Then one seems to be having trouble breathing. No other signs of stress or problems. One dies and a week later another dies. No issues with nitrite or ammonia. No one else has problems. I am assuming here that the water was too hard and too alkaline for them. I thought it would be ok but maybe not. At this point I was getting pretty frustrated.

No new additions as I was too scared because of the mortality rate. So last week, one Chromide is getting really picked on. He fins are damaged and he looks bad, starting to get pale. So i put him in a tank with my Bumble Bee Gobies. At first he seems to improve and perks up, but then he loses color and turns almost white and dies.

THEN, in the main tank the same thing happens to the other Chromide. He turns pale and dies. WTF?? They were doing fine for a couple of months at this point.

I tested everything. 0 ammonia, 0 nitrite, and then i tested nitrate. This seemed high. It was hard to tell with the stupid card but it could have been as high as 60-80 maybe higher, i just can' tell with the dumb card.

I have been doing weekly water changes with siphoning the gravel. I did one right when i saw this and removed all rocks and such to make sure i got any nastiness. After the change, the nitrate reading was def lower (but still hard to tell, maybe like 40 or so)

So I was sorta assuming that the nitrates killed the Chromides but i have been reading that puffers are nitrite and nitrate intolerant. If this was the problem, wouldn’t the GSP and F8 been affected first?

Also the Knights have been doing great. Growing and eating without an issue. Archerfish seems happy as well as the puffers.

Now, I realize that the GSP and archer need a higher SG then the F8 and knights but I was planning on moving them to a bigger tank with a higher SG as they mature. (All are still small at this time).

Can anyone comment on this situation? I realize I have probably made some mistakes with adding fish inappropriately but I have tried to research first and thought i was doing ok.

I would like any advice on what i did wrong and what i need to do going forward.


Thanks!

 

[nmonks]

Hi there,

Yep, you seem to be having some bad luck. There is a bit of voodoo to setting up a new tank. In my opinion, there's more to creating a mature tank than cycling it. That's one of the reasons I don't do fishless cycling. Tanks seem to have a certain carrying capacity that goes up with age, and there are weird factors with immature thanks that lead to unpredictable deaths. So I tend to opt for a traditional cycling method, adding two or three fish at a time over a few months, and then watch how things turn out.

Anyway, don't be disheartened.

First off, 29 gallons is a little small for the variety of fish you've tried out. Archerfish are at least 15 cm long when mature depending on the species, and dragon gobies, by which I assume you mean Gobioides, gets even bigger, easily 50 cm. In a tank your size, I'd tend to stick with things like small gobies, dwarf cichlids, glassfish, halfbeaks, etc.

Yes, dragon/violet gobies can be picky about food. They don't need to filter feed though, and most will take bloodworm, algae wafers, catfish pellets, brine shrimp, and all kinds of alternative foods. I do recommend a sandy substrate though, and another useful addition is a PVC tube into which the fish can hide. This seems very important to them.

Kribs aren't really brackish water fish, even though they are found in the Niger Delta. They prefer neutral freshwater, and that is essential if you want to breed them and have a balanced ratio of males to females in the brood. If you do keep them in brackish, I'd go 1.003, no more. But basically don't bother, and stick with the chromides.

Nitrates are rarely the cause of death with most fish. My tank routinely has a nitrate level of 60 to 100 mg/l, and my three South American puffers are as happy as Larry. There are some nitrate sensitive fish (like mbu puffers, for example) but not that many. Nitrates are more of an issue in marine tanks, in my experience.

Anyway, most archers are fine at SG 1.005, which will suit the figure-8 and the knight gobies, as well as the orange chromides. Yes, some archers like it a bit saltier, but it isn't as important as, say with monos and scats. Provided the pH is high (around 8.0) and the hardness is very high, absolute salinity is much less important than some people believe. I suspect the archer would eat the BBGs eventually though, and the kinght gobies certainly will.

Can you remind me again what and how many of each species you have in the tank now? For now, my basic advice is not to worry, just let things run as they are for a couple of weeks, if not longer. My experience is that over time tanks stabilise, and during the first few weeks and months unexplainable deaths do happen and these aren't anything to do with disease and everything to do with impatience. I'm sure advocates of fishless cycling methods may know more of that technique in detail, but as I say, I have no experience of it.

Cheers,

Neale

 

[ac106]

Hi Neale

The tank currently has

`Archerfish
1 Green spotted puffer
2 knight gobies

the Figure 8 died last night.

I have a separate tank with the bumble bees

My plan from the beginning was to move the archer GSP and dragon to a 55g when they got larger and then to break them off: The GSP into a marine tank with a green wolf eel and the archer and dragon in a bigger tanks as nessasary with appropriate tankmates. Wishfull thinking I suppose.

They fish seem ok for now but if that GSP dies my wife may have a freak out. It's her baby

 

[nmonks]

OK, if it was me, I'd leave things as they are and not add any new fish for quite a while. I'd lower the temperature a little, too; this does two things: it increases the oxygen capacity of the water, and it also reduces the metabolic rate of the fish. This only works up to a point, as obviously tropical fish can't be kept too cold, but I'd set things around the 22-24C level for the time being. Archers, it has to be said, like things a bit on the warm side, so this is strictly a temporary measure for while the tank settles down.

Now, I'd also review my feeding strategy. Frozen foods, for example, are great, but they tend to saturate the tank with dissolved and particulate organics. In other words, the "juice" that comes with the frozen bloodworms or whatever. So instead of putting a cube of frozen food into the tank, I'd thaw the stuff out in a plastic cup (I use the measuring cups that come with medicines) and then use tweezers to drop the bloodworms or krill or whatever into the tank.

About 30 minutes after feeding, I'd do a nitrite test, and then another one 60 minutes later. You see, the nitrites peak shortly after feeding, so even if the water stats seem fine most of the time, you could be missing the spike that's doing the harm. It's perfectly normal for a tank to have a trace of nitrite in the water after feeding, but anything more than a trace suggests the filter isn't working properly.

I'd also look at aeration. Regardless of the tank, I always configure the return of water from the filter so that it splashes or makes waves. You don't need bubbles to aerate the water, but you do need turbulence. Most marine fish (including puffers) are much less tolerant of low oxygen tensions than freshwater fish (such as barbs).

Above all else, I'd confine maintenance to water changes and gravel cleaning, and LEAVE THE FILTER ALONE. While properly maintaining a filter is important, unnecessary messing about with filter does more harm than good. It's important not to fuss, and let the bacteria do their thing. When setting up a tank from scratch, I invariably leave the filter alone for at least two months, sometimes more. Only when the return of water is obviously far reduced because the media is clogged, do I then switch off the filter and give it a clean. Even then, such clean is limited to rinsing a bit of media and perhaps replacing the pre-filter wool. Nothing more; ideally, have the filter back and running withing a few minutes.

Cheers,

Neale

 

[SLC Flyfishing]

Something that I have been reading up on recently both in school and on this forum is the concept of biofilms. This is a type of slime coating that grows on all sorts of surfaces and in the medical world is can pose problems. However, in a fish tank it develops over time and contains all sorts of microscopic critters. these critters are coming into view as a possible culprit as to why older tanks seem to be able maintain a healthy environment easier, and support more fish than very young ones.

I know that is an oversimplification of the issue and probably does not offer and help for ac106. However I bring it up to point out that it is becoming increasingly evident that untill these "biofilms" develop (no pun intended) some fish deaths are to be expected. There was a thread not too long ago in the tropical chit chat section of this forum that addressed this topic. I'd give it a read, might help you feel better.

P.S. ac106, why do you think it is that wives are always emotionally attached to GSP's? My wife is not into aquaria at all but she always makes it clear that if I do anything to hurt the GSP, she will not forgive me.

Good Luck

SLC

 

[phlawed]

Something that I have been reading up on recently both in school and on this forum is the concept of biofilms. This is a type of slime coating that grows on all sorts of surfaces and in the medical world is can pose problems. However, in a fish tank it develops over time and contains all sorts of microscopic critters. these critters are coming into view as a possible culprit as to why older tanks seem to be able maintain a healthy environment easier, and support more fish than very young ones.

I know that is an oversimplification of the issue and probably does not offer and help for ac106. However I bring it up to point out that it is becoming increasingly evident that untill these "biofilms" develop (no pun intended) some fish deaths are to be expected. There was a thread not too long ago in the tropical chit chat section of this forum that addressed this topic. I'd give it a read, might help you feel better.

P.S. ac106, why do you think it is that wives are always emotionally attached to GSP's? My wife is not into aquaria at all but she always makes it clear that if I do anything to hurt the GSP, she will not forgive me.

Good Luck

SLC

I wouldnt be worried about what might hurt the GSP, I would be worried about what the GSP might hurt. Gobies will make a good snack in time. Especially their tasty fins.

 

[CFC]

PH is pretty high. It's 8+ out the tap and higher then my kit goes

This is the part that worried me, all the test kits ive used measure up to pH11 and if your water is reading higher than that you have some seriously alkeline water. If this is the case then it is probably this super high pH that is causing your lower end brackish fish to die off, even marine tanks only have a pH of around 9 so keeping fish like knight gobies and kribs at these ranges is like keeping them in a bucket of diluted bleach.

Something in the tank has to be raising the pH up to this levels and needs to be removed before remedial water changes can be dont to get the pH down to a more acceptable level. The most likely cause is rocks if you have any though many substrates can have the same effect.

 

[nmonks]

Calcareous substrates (like coral sand) shouldn't raise the pH much about 8.5. They work as buffers, and dissolve to an equilibirum, i.e., they stop dissolving once it gets to a certain pH, and only begin to dissolve again if the pH drops. So now matter how much coral sand or tufa rock you stick in an aquarium, it isn't going to get much more alkaline than 8.5. That why they're called buffers rather than strong alkalis. Therefore I honestly don't think a bit of coral sand is the issue.

Are you sure you're using the pH kit properly? None of your fish would be alive if it really said the pH was off the scale. Without seeing your system or testing your water, I'm assuming you have the standard hard, South East England water with a pH around 7.8 to 8.2 out of the tap. I will say this: those dipstick pH and water chemistry test strips are nice but they're difficult to read. If you're using one of those types, be really careful how you read the results.

My guess is that because the pH is relatively high (let's say 8.2), ammonium is much more toxic than at lower pHs. So in a tank that is perhaps overstocked relatively to maturity and stability of the filter, after feeding you get spikes of ammonium that poison the fish. If it was a problem with the pH going "through the roof", then all the fish would be dead by now. You need to get an accurate pH test right now of the water in the aquarium: if it's off the scale of your present kit, go buy another one, ideally one for marine aquaria. If the pH is 9.0, then CFC has (yet again) diagnosed the situation. If the pH is merely 8.2 or 8.5, then pH isn't the issue.

Kribs just shouldn't be kept in this system regardless. No personal experience of knight gobies so I'm happy to agree with CFC on those, too. Given your mix of fish, at SG 1.005 all your fish will be happy except kribs and the GSP; at 1.010, you'd do best without the knight gobies and maybe without the fig-8s.

Cheers,

Neale

 

[ac106]

Hi guys

In regards to the PH issue:

I am from northeast US not England. Here is an excerpt from the FAQ from my water company

"What is the pH of MWRA drinking water?

MWRA treats its drinking water so that it has a pH of approximately 9.3, a slightly alkaline measurement. This pH level helps prevent water from picking up any metal particles that might be in your household plumbing."


They also add small amounts of ammonia to the water, so i switched to Amquel from Stress Coat. However this was months and months ago and i dont think is the cause of my recent deaths.

Here is another thing. I have had a freshwater tank from almost a year and have used tap water without a problem. Plus i have had a bumble bee goby tank with the same crushed coral substrate using tap water for 7-8 months, and havent lost one. In fact all are growing, very active and are pigs at feeding time.

The knight gobies were one of the first addtionins to this problem and they have been doing fine.

My test kit only goes to like 8 or something. I never bothered to get the "high end PH" test kit because well, the Ph in my tanks never seemed to be an issue. Plus i have read over and over on this forum that people messing around with ph get into more trouble then leaving it alone.

As for some other advice above. I never play with the filters except to rinse the sponges in the water change water once a month or so. If i clean the filter itself it's only to dunk it in the water change bucket. I do weekly 5gal water changes using amquel because there is ammonia in my tap water.

I have considered the high end ph killed off the kribs, and i wasnt going to try them again in this tank. I am not sure its the cause of the chromide deaths as they were doing seemingly fine for several months and then both died in consecutive days.

I am def open to the idea though. What can i do about the high PH?

 

[nmonks]

Well, I still think you need a pH test kit that spans the 7 to 9 range. Any will do. But you do need to know if the pH is just off the scale, e.g., 8.2, or way off, 9.0. A pH of 9 is insanely high, and far too high for freshwater aquarium fish. You do need to lower it. For brackish, 8.0 is adequate. Can you collect rainwater? I use that to dilute tap water and so maintain aquaria with a much lower pH and hardness than the tap water alone would allow. Rainwater butts are cheap and though there are small risks from pollution, the benefits offset those in my experience.

I would suspect the pH of water quoted by the water board includes the ammonia; once you remove the ammonia, the pH will drop, probably to around 8 point something. Do a test, otherwise at the moment any discussion here is really just speculation.

Cheers,

Neale

 

[ac106]

Ok, that sounds good. I will pick one up within a day or so and post the results.

Thanks again!

Adam

 

[ac106]

OK i got a high range PH kit, it goes up to 8.4. The LFS didnt have one that went higher or i would have grabbed it instead. Anyway here are the surprising results ( to me anyway)

PH in tank: 7.8-8 -- I am surprised as hell by this but i did it twice. I have a deep layer of crushed coral and a bunch of sea shells from the ocean, I just cannot believe its this low.

PH in tap: 8.6 or possibly higher cant really tell, its a deep purple

PH of tap after using Amquel and sitting for 24 hours: 8.2

I find this all pretty interesting. For one, why isn't the crushed coral buffering the water higher? ( I guess i am not complaining but curious as to why not).

Any rhyme or reason for the above?

 

[nmonks]

Two reasons. Crushed coral is a buffer, not a hardening agent. There's a subtle difference. Buffers dissolve at a rate proportional to a certain pH/hardness. The closer to that optimal level the water goes, the slower the dissolution rate gets, and once that level is reached, net dissolution stops altogether. For coral sand, that optimal level is around 8.0.

Secondly, coral sand in a substrate (or in a filter for that matter) is not a very good buffering agent, much less good than people imagine. After a couple of weeks of use, each grain is covered in something called a biofilm, a layer of bacteria and algae that effectively isolate the coral sand grain from the water, inhibiting dissolution. Think of those Minstrels chocolates, where the crispy coating stops the chocolate melting in your hand. It's like that.

When you clean the gravel, or at least stir it a bit, some of the biofilm gets abraded and the buffering capacity returns, but that's about all you can do. This is why marine aquarists rely on things like kalkwasser to harden water and not just the tufa rock and coral sand.

Anyway, it sounds as is things are okay in the tank. As I thought, the pH dropped considerably after adding the ammonia remover. The pH of water in an aquaria tends to drop a little anyway, because of various metabolic processes of the fish as well as background decay of organic waste, so the pH is probably going to hover around the 8.0 mark, up on down a notch won't matter much. I still think you should just leave things a couple of weeks and see how events pan out. Test the nitrites after feeding, and see how the filter is behaving, I think that's your next issue. One other thing to consider is oxygen level. Virtually all brackish water fish are intolerant of low oxygen concentrations. Have you optimised the return of water from the filter so that it creates turbulence? That's the single best way to add extra oxygen. Even if your tank isn't overstocked, a variety of things can cause oxygen concentration to go down: a large filter, decaying plants, etc.

Cheers,

Neale

I find this all pretty interesting. For one, why isn't the crushed coral buffering the water higher? ( I guess i am not complaining but curious as to why not).
Any rhyme or reason for the above?

 

[ac106]

Heya Neale,


As far as oxygen level. I have 2 x Aqua Clear 30s. I killed the current on one with some plastic as it was distrubing my plants. However, I have an 8" airstone and a box filter on opposite sides of the tank.

Is this sufficient for surface agitation? I can remove the plastic if that will make a difference. Even with the flow unblocked it doesn't overly distrub the water.

I may have the oppurtunity to acquire a used canister filter for a good price. Should i consider switching over or is this setup sufficient?

 

[nmonks]

Adding any sort of water movement helps, but remember, filter bacteria use up oxygen too. That's why marine aquarists (who have to deal with very oxygen-sensitive livestock) often use additional powerheads rather than filters: the water movement is improved without adding another draw on oxygen supplies.

An airstone will help, of course, as will orienting the return of water so it splashes more. Venturi jet returns work well, as to spray bars (very underrated but useful bits of kit). Also check the circulation of the water is more or less uniform around the tank. Make sure there aren't any dead spots.

But my gut feeling is all of this is irrelevant; I suspect your tank is merely immature and still at that unstable point where its loading capacity fluctuates. Do some nitrite tests after feeding, see how things look, and just sit on your hands for a couple of weeks. If nothing dies, then you're probably out of the woods.

Cheers,

Neale